Russia will do a nuclear test

A thought occurred to me, and it’s so logical, I concluded that it must be true.

Russia will not detonate a nuclear weapon in Ukraine, fearing repercussion.

Russia will detonate a nuclear weapon in Russia. In other words, Russia will do a nuclear test. Like North Korea did.

As far as I know, there is no international law against Russia doing a nuclear test. Russia is a recognized nuclear weapon state of NPT, unlike North Korea. The test will give weight to Putin’s words that he is not bluffing.